Mam is closely related to the Tektitek language, and the two languages together form the Mamean sub-branch, which together with the Ixilean languages, Awakatek and Ixil, form the Greater Mamean sub-branch. Together, Greater Mamean and the Greater Quichean languages (consisting of 10 Mayan languages, including K'iche'), form the Quichean–Mamean branch.

Because of Spanish colonial policy, which enforced a harsh penalty upon the written use of indigenous languages, the language can vary widely from village to village. Because of the lack of a standardized written dialect throughout the colonial era, different villages developed regional accents which evolved into full differentiated dialects, even though the villages may only be a few miles apart from each other. Furthermore, the Mam people have continually occupied their present-day territory, long before the Spanish Conquest, possibly as early as 500 A.D. according to linguist Terrence Kaufman (England 1983:6). This would explain the great dialectal diversity among the Mamean languages. Kaufman also suggests that the Sierra de los Cuchumatanes of Huehuetenango, which currently occupied mostly by speakers of Mamean languages.

The Mid-central vowel is an allophone of short a, e and u that can occur in the syllable following a stressed long vowel.

Like in many other Mayan languages, vowel length is contrastive, and short and long vowels have different phonemic values and are treated as separate vowels. The long versions the back vowels, /o/, /u/, /ɑ/ vowels, transcribed as [oo], [uu], and [aa] are slightly compressed and pronounced as /o͍ː/, /u͍ː/, and /ɑ͍ː/ respectively, being partially rounded.

In the Todos Santos dialect the vowel structure is somewhat different. While /o/, /a/, and /u/ remain the same as in other varieties, short /e/ has become the diphthong /ɛi/, an audio example of this can be heard here:[5]

In the Todos Santos dialect, the long vowels (distinguished by the doubling of the letter) have evolved into separate sounds altogether. Long /aː/ has become /ɒ/, long /oː/ has become /øː/ and long /uː/ has become /yː/.

In some dialects vowels interrupted by stop have evolved into individual phonemes themselves, for example in Todos Santos dialect /oʔ/ represented by o' has evolved into /ɵʏˀ/ and /oʔo/ represented by o'o has evolved into /ɵ'ʉ/.

/ɓ/ is realized as [βʼ] word-finally and when part of a consonant cluster in many dialects. In the Todos Santos dialect it is pronounced as [v] as part of a consonant cluster and as [βv̻] word finally.

Examples: tzeb' [tsɛβʼ] goat, kbon [kβʼɤŋ] small table. In the Todos Santos dialect, tseb' is [tsɛiβv̻] and kbon is [kvoŋ] small table.

/p/ is realized as [pʰ] word-finally and word initially, [p] elsewhere, [ɸ] in a consonant cluster and before short i, o, and u. It is pronounced as [ɸʰ] word finally in certain dialects. [f] is an interchangeable pronunciation of [ɸ].

/w/ can be pronounced [ʋ], [v], [v̥] or [β] word initially, [w], [ʍ] [ʋ] following a consonant, and [ʋ], [v], [v̻ʰ] or [fʰ] word finally. It is freely variable between [w] [v] [ʋ] [v̥] in all other positions with [ʋ] being the most common pronunciation. In the Todos Santos dialect, /w/ is realized as either [v] or [ʋ] word-initially or between vowels and before another consonant, as [ʍ] following a consonant and as [v̥] word finally.

/ky/ is realized as [kɕʲ] in front of another consonant and kɕʰ word finally. It is pronounced as kʲ in all other instances.

Examples: kyja'tzan [kɕʲχaʲʔtsʰaŋ], kyokleen [kʲɤkleːŋ]

/ ' / is realized as [ʲʔ] following /a/, /aa/, /e/, /ee/, /i/, /u/, /uu/ and /oo/. The standard pronunciation is simply [ʔ] after all vowels however in spoken speech [ʲʔ] is the common pronunciation. A similar trend can be seen in other Eastern Mayan languages. After /o/ it is pronounced as [ʉʔ] and after /ii/ it is pronounced simply as [ʔ]. Following consonants / ' / modifies each individual consonant differently as explained in the section above. In the Mam language every word must start with a consonant. In the current orthography initial / ' / is not written but if a word ever begins with a vowel, the word is treated as if it begin with a / ' /. The initial / ' / may be pronounced as either [ʔ] or [ʡ] in free variation.

The basic word order of Mam is VSO (Verb-Subject-Object, Verb-Ergative-Absolutive, or Verb-Agent-Patient). Most roots take the morphological shape CVC (England 1983:93). The only possible root final consonant cluster is -nC.

Below is a table of Set A (ergative) and Set B (absolutive) prefixes from England (1983:56). (Note: The terms "Set A" and "Set B" are frequently used by Mayanists to describe the ergative systems typical of Mayan languages.)

Mam Set A and Set B Pronominal Markers

Person

Set A

Set B

Enclitics

1s

n- ~ w-

chin-

-a ~ -ya

2s

t-

Ø ~ tz- ~ tz'- ~ k-

-a ~ -ya

3s

t-

Ø ~ tz- ~ tz'- ~ k-

-

1p (excl.)

q-

qo-

-a ~ -ya

1p (incl.)

q-

qo-

-

2p

ky-

chi-

-a ~ -ya

3p

ky-

chi-

-

Phonologically conditioned allomorphs are as follows.

n- ~ w-

n- /__C

w- /__V

Ø ~ tz- ~ tz'- ~ k-

k- /potential

tz'- /__V initial root, non-potential

tz- /__uul 'arrive here', iky' 'pass by', non-potential

Ø- /__C, non-potential

-a ~ -ya

-ya /V__ ; In the first person in post-vowel environments, -ya varies freely with -ky'a and -y'.

-a /C__

When Set A prefixes can also be used with nouns. In this context, the Set A prefixes become possessives.

n- 'my'

t- 'your (sg.)'

t- 'his, her, its'

q- 'our (exclusive)'

q- 'our (inclusive)'

ky- 'your (pl.)'

ky- 'their'

Some paradigmatic examples from England (1983) are given below. Note that "Ø-" designates a null prefix. Additionally, ma is an aspectual word meaning 'recent past.'

Set A markers + NOUN

jaa

‘house’

n-jaa-ya

‘my house’

t-jaa-ya

‘your house’

t-jaa

‘his/her house’

q-jaa-ya

‘our (not your) house’

q-jaa

‘our (everyone’s) house’

ky-jaa-ya

‘you (pl)’s house’

ky-jaa

‘their house’

Set B markers + VERB

b'eet-

to walk

ma chin b'eet-a

'I walked.'

ma Ø-b'eet-a

'You walked.'

ma Ø-b'eet

'He/she walked.'

ma qo b'eet-a

'We (not you) walked.'

ma qo b'eet

'We walked'

ma chi b'eet-a

'You all walked.'

ma chi b'eet

'They walked.'

The following Set B person markers are used for non-verbal predicates (i.e., nouns, adjectives). Also, in statives, aa can be omitted when the rest of the stative is a non-enclitic (in other words, a separate, independent word).

The Mam language displays inalienable possession. Certain Mam nouns cannot be possessed, such as kya7j 'sky' and che7w 'star' (England 1983:69). On the other hand, some Mam nouns are always possessed, such as t-lok' 'its root' and t-b'aq' 'its seed'.

Noun phrase structure can be summarized into the following template (England 1983:140).

San Ildefonso Ixtahuacán Mam numbers are as follows (England 1983:84). Numbers above twenty are rarely used in Ixtahuacán and are usually only known by elderly speakers. Although the number system would have originally been vigesimal (i.e., base 20), the present-day number system of Ixtahuacán is now decimal.